Award: OCE-1437266

The 2015 US GEOTRACES Arctic research cruise was unique, representing the first time a US ship had reached the North Pole unaccompanied. While we focused our research on the western Arctic, colleagues from Canada and Europe conducted their own research cruises at the same time, representing a truly pan-Arctic research project to study the distributions and behavior of a broad suite of biologically essential trace elements (micronutrients), water-mass mixing tracers, and tracers of paleo-oceanographic importance. Our project included a wide array of outreach activities. Bill Schmoker, our on-board PolarTREC science teacher, posted over 65 blogs (with descriptive text and photos) to the PolarTREC web site: www.polartrec.com/expeditions/us-arctic-geotraces/journals. In addition, Journals and videos from Bill Schmoker are posted at https://www.polartrec.com/expeditions/us-arctic-geotraces and https://www.youtube.com/user/PolarTRECProgram/. Florida International University produced a very high quality video of the research expedition, "Journey to the top of the world" http://arctic.fiu.edu/. We engaged hundreds of young students through our "Float Your Boat" outreach project. Over 1300 small wood boat forms were decorated by students from around the US with their names and contact information, then deployed on the ice in the Arctic along with satellite tracking buoys so they could be followed as the ice moves through the Arctic. Eventually, the ice will melt and the boats and buoys will be released into the water where tracking can continue. If we are lucky, some of the boats will wash ashore, where they will be found and their recovery positions will be reported back to the students. https://www.facebook.com/explorethearctic/ Our work on the 2015 US GEOTRACES cruise to the western Arctic Ocean (HLY1502; GEOTRACES cruise GN01) focused on the collection and analysis of atmospheric samples (aerosols and freshly falling snow). We were primarily interested in characterizing the composition of atmospheric particles (aerosols) in the summertime Arctic with a focus on their trace element chemistry. These aerosols can be produced by both natural and anthropogenic processes in both marine and continental environments. Despite their low abundance, trace elements often play a significant role in marine productivity because they are essential micronutrients for cellular metabolic pathways and enzyme functions. Deposition from the atmosphere can be the primary source of trace elements to the surface ocean; a process complicated by ice cover in the Arctic. We determined concentrations of many trace elements Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb as well as P, Sc, and Cr. Falling snow was also analyzed for particulate and dissolved trace elements. We measured the solubility of aerosols in ultrapure deionized water, filtered surface seawater, and a strong acid solution allowing us to estimate the fractional solubility of aerosols reaching the surface ocean by wet and dry deposition. When possible, we collected water samples from ponds of melted water which form on the surface of the sea ice. These unique environments impact the rate at which material from the atmosphere reaches the surface ocean. Dr. Christopher Marsay, a postdoctoral scientist, participated on the cruise. We also provided aerosol and melt-pond samples to other cruise participants. The data has been submitted to the appropriate NSF and GEOTRACES data repositories. Last Modified: 03/25/2019 Submitted by: William M Landing